As far as I know, it's not legally required, at least in the US, though I wouldn't be surprised if suggestions from gov behind the scenes were the inspiration f

As far as I know, it's not legally required, at least in the US, though I wouldn't be surprised if suggestions from gov behind the scenes were the inspiration for this. I guess the EU is in the process of trying to mandate something like this. Which would be unfortunate. At that point, you won't be able maintain digital privacy from the govt w/o de-facto becoming a criminal. CSAM is, I think, simply the initial justification for these systems, since it's widely reviled. But the system itself is not CSAM-specific, and the temptation to expand its scope will likely be irresistible. If your goal was to become an authoritarian tyrant, you would be very happy to have this in place. :-)